Forest Fire Smoke Layers Observed in the Free Troposphere over Portugal with a Multiwavelength Raman Lidar: Optical and Microphysical Properties
Vertically resolved optical and microphysical properties of biomass burning aerosols, measured in 2011 with a multiwavelength Raman lidar, are presented. The transportation time, within 1-2 days (or less), pointed towards the presence of relatively fresh smoke particles over the site. Some strong la...
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| Format: | Article |
| Language: | English |
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Wiley
2014-01-01
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| Series: | The Scientific World Journal |
| Online Access: | http://dx.doi.org/10.1155/2014/421838 |
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| author | Sérgio Nepomuceno Pereira Jana Preißler Juan Luis Guerrero-Rascado Ana Maria Silva Frank Wagner |
| author_facet | Sérgio Nepomuceno Pereira Jana Preißler Juan Luis Guerrero-Rascado Ana Maria Silva Frank Wagner |
| author_sort | Sérgio Nepomuceno Pereira |
| collection | DOAJ |
| description | Vertically resolved optical and microphysical properties of biomass burning aerosols, measured in 2011 with a multiwavelength Raman lidar, are presented. The transportation time, within 1-2 days (or less), pointed towards the presence of relatively fresh smoke particles over the site. Some strong layers aloft were observed with particle backscatter and extinction coefficients (at 355 nm) greater than 5 Mm−1 sr−1 and close to 300 Mm−1, respectively. The particle intensive optical properties showed features different from the ones reported for aged smoke, but rather consistent with fresh smoke. The Ångström exponents were generally high, mainly above 1.4, indicating a dominating accumulation mode. Weak depolarization values, as shown by the small depolarization ratio of 5% or lower, were measured. Furthermore, the lidar ratio presented no clear wavelength dependency. The inversion of the lidar signals provided a set of microphysical properties including particle effective radius below 0.2 μm, which is less than values previously observed for aged smoke particles. Real and imaginary parts of refractive index of about 1.5-1.6 and 0.02i, respectively, were derived. The single scattering albedo was in the range between 0.85 and 0.93; these last two quantities indicate the nonnegligible absorbing characteristics of the observed particles. |
| format | Article |
| id | doaj-art-f97bd70198634edb8f0b74bd119a29e5 |
| institution | Kabale University |
| issn | 2356-6140 1537-744X |
| language | English |
| publishDate | 2014-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | The Scientific World Journal |
| spelling | doaj-art-f97bd70198634edb8f0b74bd119a29e52025-02-03T01:32:49ZengWileyThe Scientific World Journal2356-61401537-744X2014-01-01201410.1155/2014/421838421838Forest Fire Smoke Layers Observed in the Free Troposphere over Portugal with a Multiwavelength Raman Lidar: Optical and Microphysical PropertiesSérgio Nepomuceno Pereira0Jana Preißler1Juan Luis Guerrero-Rascado2Ana Maria Silva3Frank Wagner4Évora Geophysics Center, Rua Romão Ramalho 59, 7000 Évora, PortugalÉvora Geophysics Center, Rua Romão Ramalho 59, 7000 Évora, PortugalÉvora Geophysics Center, Rua Romão Ramalho 59, 7000 Évora, PortugalÉvora Geophysics Center, Rua Romão Ramalho 59, 7000 Évora, PortugalÉvora Geophysics Center, Rua Romão Ramalho 59, 7000 Évora, PortugalVertically resolved optical and microphysical properties of biomass burning aerosols, measured in 2011 with a multiwavelength Raman lidar, are presented. The transportation time, within 1-2 days (or less), pointed towards the presence of relatively fresh smoke particles over the site. Some strong layers aloft were observed with particle backscatter and extinction coefficients (at 355 nm) greater than 5 Mm−1 sr−1 and close to 300 Mm−1, respectively. The particle intensive optical properties showed features different from the ones reported for aged smoke, but rather consistent with fresh smoke. The Ångström exponents were generally high, mainly above 1.4, indicating a dominating accumulation mode. Weak depolarization values, as shown by the small depolarization ratio of 5% or lower, were measured. Furthermore, the lidar ratio presented no clear wavelength dependency. The inversion of the lidar signals provided a set of microphysical properties including particle effective radius below 0.2 μm, which is less than values previously observed for aged smoke particles. Real and imaginary parts of refractive index of about 1.5-1.6 and 0.02i, respectively, were derived. The single scattering albedo was in the range between 0.85 and 0.93; these last two quantities indicate the nonnegligible absorbing characteristics of the observed particles.http://dx.doi.org/10.1155/2014/421838 |
| spellingShingle | Sérgio Nepomuceno Pereira Jana Preißler Juan Luis Guerrero-Rascado Ana Maria Silva Frank Wagner Forest Fire Smoke Layers Observed in the Free Troposphere over Portugal with a Multiwavelength Raman Lidar: Optical and Microphysical Properties The Scientific World Journal |
| title | Forest Fire Smoke Layers Observed in the Free Troposphere over Portugal with a Multiwavelength Raman Lidar: Optical and Microphysical Properties |
| title_full | Forest Fire Smoke Layers Observed in the Free Troposphere over Portugal with a Multiwavelength Raman Lidar: Optical and Microphysical Properties |
| title_fullStr | Forest Fire Smoke Layers Observed in the Free Troposphere over Portugal with a Multiwavelength Raman Lidar: Optical and Microphysical Properties |
| title_full_unstemmed | Forest Fire Smoke Layers Observed in the Free Troposphere over Portugal with a Multiwavelength Raman Lidar: Optical and Microphysical Properties |
| title_short | Forest Fire Smoke Layers Observed in the Free Troposphere over Portugal with a Multiwavelength Raman Lidar: Optical and Microphysical Properties |
| title_sort | forest fire smoke layers observed in the free troposphere over portugal with a multiwavelength raman lidar optical and microphysical properties |
| url | http://dx.doi.org/10.1155/2014/421838 |
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